Communities

1. Communities

2. Communities • All populations interacting at any particular time in a defined habitat. - Give me an example?

3. Communities • All populations interacting at any particular time in a defined habitat. • Some are temporary (eg. a rotting log) and some last a long time (eg. Forests) Other examples?

4. Communities • All populations interacting at any particular time in a defined habitat. • Some are temporary (eg. a rotting log) and some last a long time (eg. Forests) • Three characteristics common to most communities: - The more different species in a community, the more stable it is = species diversity. And vice versa. Eg. Tundra – unstable b/c low species diversity, rainforest – stable.

5. Three characteristics common to most communities: • A few organisms are present in a large number or great biomass (weight of living matter). These dominate the community.

6. Three characteristics common to most communities: • A few organisms are present in a large number or great biomass (weight of living matter). These dominate the community. A great number of other organisms are relatively rare, but they can play an important role.

7. Three characteristics common to most communities: • A few organisms are present in a large number or great biomass (weight of living matter). These dominate the community. A great number of other organisms are relatively rare, but they can play an important role. • EG. A beetle that only eats one plant may keep it in check.

8. Three characteristics common to most communities: • Always more producers (usually plants) than consumers. (One exception – the sea). Phytoplankton don’t have higher numbers than animals that eat it, yet they reproduce so quickly they can keep up.

9. Three characteristics common to most communities: • Always more producers (usually plants) than consumers. (One exception – the sea). Phytoplankton don’t have higher numbers than animals that eat it, yet they reproduce so quickly they can keep up. • ** Communities are named from the highest biomass – eg a kauri forest.

10. Composition of a community • All organisms can be grouped according to their feeding or trophic levels. • Producers –

11. Composition of a community • All organisms can be grouped according to their feeding or trophic levels. • Producers – make their own food Photosynthesisers = take energy from sunlight. Together with water and C02 they make glucose.

12. Composition of a community • All organisms can be grouped according to their feeding or trophic levels. • Producers – make their own food Photosynthesisers = take energy from sunlight. Together with water and C02 they make glucose. Chemosynthesisers = usually bacteria. Same thing but energy from chemical reactions.

13. Chemosynthesis

14. 2. Consumers – can’t make own food.

15. 2. Consumers – can’t make own food. • Herbivores = animals that eat all parts of plants. Sap, leaves, roots, pollen etc.

16. 2. Consumers – can’t make own food. • Herbivores = animals that eat all parts of plants. Sap, leaves, roots, pollen etc. • Carnivores = animals that eat other animals. Predators – hunt, kill, and eat.

17. 2. Consumers – can’t make own food. • Herbivores = animals that eat all parts of plants. Sap, leaves, roots, pollen etc. • Carnivores = animals that eat other animals. Predators – hunt, kill, and eat. • Scavengers – live off dead animals killed by something else.

18. 2. Consumers – can’t make own food. • Herbivores = animals that eat all parts of plants. Sap, leaves, roots, pollen etc. • Carnivores = animals that eat other animals. Predators – hunt, kill, and eat. • Scavengers – live off dead animals • Parasites – live in or on living host. Endo-inside, and Ecto-outside.

19. Endo/Ecto

20. 2. Consumers – can’t make own food. • Herbivores = animals that eat all parts of plants. Sap, leaves, roots, pollen etc. • Carnivores = animals that eat other animals. Predators – hunt, kill, and eat. • Scavengers – live off dead animals • Parasites – live in or on living host. Endo-inside, and Ecto-outside. • Decomposers = bacteria and fungi that break down dead bodies to release the nutrients.

21. Intra-specific relationships • Either cooperative or aggressive.

22. Intra-specific relationships • Either cooperative or aggressive. • Cooperative – includes courtship, looking after young, hunting in packs, defending the group.

23. Intra-specific relationships • Either cooperative or aggressive. • Cooperative – includes courtship, looking after young, hunting in packs, defending the group. • Aggressive – fighting for mates, territory, keeping up pecking order etc.

24. Inter-specific relationships • Mutualism – both partners benefit. (lots of examples which we have already discussed/watched  jot down some)

25. Inter-specific relationships • Mutualism – both partners benefit. • Commensalism – one species benefits while the other is unaffected. EG. A fish called a remora. Hitches a ride on a shark, and when the shark attacks the remora feeds on scraps then hitches another ride. The sharks are indifferent, yet the remora gets lots of food and doesn’t use energy.

26. Inter-specific relationships • Mutualism – both partners benefit. • Commensalism – one species benefits while the other is unaffected. • Antibiosis – one species is harmed and the other is indifferent. EG. Blue green mould on rotting oranges/lemons is penicillum – which produces a chemical called penicillin which inhibits bacteria. Hence, antibiotics.

27. Inter-specific relationships • Mutualism – both partners benefit. • Commensalism – one species benefits while the other is unaffected. • Antibiosis – one species is harmed and the other is indifferent. • Exploitation – One species benefits, while the other is harmed. EG. Most examples of herbivores, carnivores, and parasites etc.